Internal combustion engines are continually being refined to decrease noise, vibration, and harshness (NVH) as well as increase the structural integrity of the connection between various components. Components coupled to the cylinder block, such as structural frame, may experience a large amount of stress during engine operation. Specifically vibrations may be transferred to the structural frame from the engine during operation.
Therefore, ladder frames have been developed which are integrally molded with the cylinder block. For example, in U.S. Pat. No. 5,357,922 a cylinder block assembly is disclosed. The cylinder block assembly includes a skirt portion and a ladder frame integrally molded with a portion of the cylinder block. When the ladder frame is integrally molded with a portion of the cylinder block, noise vibration and harshness (NVH) in the engine may be reduced.
However, the inventors herein have recognized various drawbacks with the cylinder block assembly disclosed in U.S. Pat. No. 5,357,922. For example, the crankshaft as well as other engine components may be difficult to install when the cylinder block and ladder frame are integrally molded. Moreover, integrally molding the cylinder block and ladder frame may restrict the shape of the ladder frame as well as decrease the amount of machining that can be performed on the ladder frame after molding.
The inventors herein have recognized the challenges of NVH reduction as well as strength to weight tradeoffs within a cylinder block assembly and have provided a cylinder block assembly comprising: a cylinder block including at least a cylinder; and a crankshaft support at a bottom side of the cylinder block, the crankshaft support including a bottom surface having a structural frame attachment recess partially extending into the crankshaft support and substantially centrally positioned with regard to first and second lateral edges of the bottom surface.
When the attachment interface between the bearing cap and structural frame is centrally positioned with regard to the lateral edges of the bearing cap, the structural integrity of the cylinder block assembly may be increased. Furthermore, when a single centrally positioned attachment recess or feature is utilized the weight of the cylinder block assembly may be reduced. Moreover, the manufacturing and installation process of the cylinder block assembly may be simplified, thereby reducing the cost of the cylinder block assembly when a single centrally positioned attachment recess or feature is utilized.
This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. Furthermore, the claimed subject matter is not limited to implementations that solve any or all disadvantages noted in any part of this disclosure.
FIGS. 3-19 are drawn approximately to scale.